/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2013-2014 sagyf Yang. The Four Group.
 */

package com.jfinal.core;

import com.jfinal.i18n.I18N;
import com.jfinal.kit.StringKit;
import com.jfinal.render.Render;
import com.jfinal.render.RenderFactory;
import com.jfinal.sog.kit.AppFunc;
import com.jfinal.sog.kit.StringPool;
import com.jfinal.sog.kit.date.DateProvider;
import com.jfinal.upload.MultipartRequest;
import com.jfinal.upload.UploadFile;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.File;
import java.text.ParseException;
import java.util.*;
import java.util.Map.Entry;

import static com.jfinal.core.Const.I18N_LOCALE;

/**
 * Controller
 * <br>
 * 昨夜西风凋碧树。独上高楼，望尽天涯路。<br>
 * 衣带渐宽终不悔，为伊消得人憔悴。<br>
 * 众里寻她千百度，蓦然回首，那人却在灯火阑珊处。
 */
@SuppressWarnings("UnusedDeclaration")
public abstract class Controller {

    private HttpServletRequest  request;
    private HttpServletResponse response;

    private String   urlPara;
    private String[] urlParaArray;

    private static final String[] NULL_URL_PARA_ARRAY = AppFunc.EMPTY_ARRAY;
    private static final String   URL_PARA_SEPARATOR  = Config.getConstants().getUrlParaSeparator();

    void init(HttpServletRequest request, HttpServletResponse response, String urlPara) {
        this.request = request;
        this.response = response;
        this.urlPara = urlPara;
    }

    public void setUrlPara(String urlPara) {
        this.urlPara = urlPara;
        this.urlParaArray = null;
    }

    /**
     * Stores an attribute in this request
     *
     * @param name  a String specifying the name of the attribute
     * @param value the Object to be stored
     */
    public Controller setAttr(String name, Object value) {
        request.setAttribute(name, value);
        return this;
    }

    /**
     * Removes an attribute from this request
     *
     * @param name a String specifying the name of the attribute to remove
     */
    public Controller removeAttr(String name) {
        request.removeAttribute(name);
        return this;
    }

    /**
     * Stores attributes in this request, key of the map as attribute name and value of the map as attribute value
     *
     * @param attrMap key and value as attribute of the map to be stored
     */
    public Controller setAttrs(Map<String, Object> attrMap) {
        for (Entry<String, Object> entry : attrMap.entrySet())
            request.setAttribute(entry.getKey(), entry.getValue());
        return this;
    }

    /**
     * Returns the value of a request parameter as a String, or null if the parameter does not exist.
     * <p/>
     * You should only use this method when you are sure the parameter has only one value. If the
     * parameter might have more than one value, use getParaValues(java.lang.String).
     * <p/>
     * If you use this method with a multivalued parameter, the value returned is equal to the first
     * value in the array returned by getParameterValues.
     *
     * @param name a String specifying the name of the parameter
     * @return a String representing the single value of the parameter
     */
    public String getPara(String name) {
        return request.getParameter(name);
    }

    /**
     * Returns the value of a request parameter as a String, or default value if the parameter does not exist.
     *
     * @param name         a String specifying the name of the parameter
     * @param defaultValue a String value be returned when the value of parameter is null
     * @return a String representing the single value of the parameter
     */
    public String getPara(String name, String defaultValue) {
        String result = request.getParameter(name);
        return result != null && !"".equals(result) ? result : defaultValue;
    }

    /**
     * Returns the values of the request parameters as a Map.
     *
     * @return a Map contains all the parameters name and value
     */
    public Map<String, String[]> getParaMap() {
        return request.getParameterMap();
    }

    /**
     * Returns an Enumeration of String objects containing the names of the parameters
     * contained in this request. If the request has no parameters, the method returns
     * an empty Enumeration.
     *
     * @return an Enumeration of String objects, each String containing the name of
     * a request parameter; or an empty Enumeration if the request has no parameters
     */
    public Enumeration<String> getParaNames() {
        return request.getParameterNames();
    }

    /**
     * Returns an array of String objects containing all of the values the given request
     * parameter has, or null if the parameter does not exist. If the parameter has a
     * single value, the array has a length of 1.
     *
     * @param name a String containing the name of the parameter whose value is requested
     * @return an array of String objects containing the parameter's values
     */
    public String[] getParaValues(String name) {
        return request.getParameterValues(name);
    }

    /**
     * Returns an array of Integer objects containing all of the values the given request
     * parameter has, or null if the parameter does not exist. If the parameter has a
     * single value, the array has a length of 1.
     *
     * @param name a String containing the name of the parameter whose value is requested
     * @return an array of Integer objects containing the parameter's values
     */
    public Integer[] getParaValuesToInt(String name) {
        String[] values = request.getParameterValues(name);
        if (values == null)
            return null;
        Integer[] result = new Integer[values.length];
        for (int i = 0; i < result.length; i++)
            result[i] = Integer.parseInt(values[i]);
        return result;
    }

    /**
     * Returns an Enumeration containing the names of the attributes available to this request.
     * This method returns an empty Enumeration if the request has no attributes available to it.
     *
     * @return an Enumeration of strings containing the names of the request's attributes
     */
    public Enumeration<String> getAttrNames() {
        return request.getAttributeNames();
    }

    /**
     * Returns the value of the named attribute as an Object, or null if no attribute of the given name exists.
     *
     * @param name a String specifying the name of the attribute
     * @return an Object containing the value of the attribute, or null if the attribute does not exist
     */
    public <T> T getAttr(String name) {
        return (T) request.getAttribute(name);
    }

    /**
     * Returns the value of the named attribute as an Object, or null if no attribute of the given name exists.
     *
     * @param name a String specifying the name of the attribute
     * @return an String Object containing the value of the attribute, or null if the attribute does not exist
     */
    public String getAttrForStr(String name) {
        return (String) request.getAttribute(name);
    }

    /**
     * Returns the value of the named attribute as an Object, or null if no attribute of the given name exists.
     *
     * @param name a String specifying the name of the attribute
     * @return an Integer Object containing the value of the attribute, or null if the attribute does not exist
     */
    public Integer getAttrForInt(String name) {
        return (Integer) request.getAttribute(name);
    }

    private Integer toInt(String value, Integer defaultValue) {
        if (value == null || "".equals(value.trim()))
            return defaultValue;
        if (value.startsWith("N") || value.startsWith(StringPool.N))
            return -Integer.parseInt(value.substring(1));
        return Integer.parseInt(value);
    }

    /**
     * Returns the value of a request parameter and convert to Integer.
     *
     * @param name a String specifying the name of the parameter
     * @return a Integer representing the single value of the parameter
     */
    public Integer getParaToInt(String name) {
        return toInt(request.getParameter(name), null);
    }

    /**
     * Returns the value of a request parameter and convert to Integer with a default value if it is null.
     *
     * @param name a String specifying the name of the parameter
     * @return a Integer representing the single value of the parameter
     */
    public Integer getParaToInt(String name, Integer defaultValue) {
        return toInt(request.getParameter(name), defaultValue);
    }

    private Long toLong(String value, Long defaultValue) {
        if (value == null || "".equals(value.trim()))
            return defaultValue;
        if (value.startsWith("N") || value.startsWith(StringPool.N))
            return -Long.parseLong(value.substring(1));
        return Long.parseLong(value);
    }

    /**
     * Returns the value of a request parameter and convert to Long.
     *
     * @param name a String specifying the name of the parameter
     * @return a Integer representing the single value of the parameter
     */
    public Long getParaToLong(String name) {
        return toLong(request.getParameter(name), null);
    }

    /**
     * Returns the value of a request parameter and convert to Long with a default value if it is null.
     *
     * @param name a String specifying the name of the parameter
     * @return a Integer representing the single value of the parameter
     */
    public Long getParaToLong(String name, Long defaultValue) {
        return toLong(request.getParameter(name), defaultValue);
    }

    private Boolean toBoolean(String value, Boolean defaultValue) {
        if (value == null || "".equals(value.trim()))
            return defaultValue;
        value = value.trim().toLowerCase();
        if (StringPool.ONE.equals(value) || StringPool.TRUE.equals(value))
            return Boolean.TRUE;
        else if (StringPool.ZERO.equals(value) || StringPool.FALSE.equals(value))
            return Boolean.FALSE;
        throw new RuntimeException("Can not parse the parameter \"" + value + "\" to boolean value.");
    }

    /**
     * Returns the value of a request parameter and convert to Boolean.
     *
     * @param name a String specifying the name of the parameter
     * @return true if the value of the parameter is "true" or "1", false if it is "false" or "0", null if parameter is not exists
     */
    public Boolean getParaToBoolean(String name) {
        return toBoolean(request.getParameter(name), null);
    }

    /**
     * Returns the value of a request parameter and convert to Boolean with a default value if it is null.
     *
     * @param name a String specifying the name of the parameter
     * @return true if the value of the parameter is "true" or "1", false if it is "false" or "0", default value if it is null
     */
    public Boolean getParaToBoolean(String name, Boolean defaultValue) {
        return toBoolean(request.getParameter(name), defaultValue);
    }

    /**
     * Get all para from url and convert to Boolean
     */
    public Boolean getParaToBoolean() {
        return toBoolean(getPara(), null);
    }

    /**
     * Get para from url and conver to Boolean. The first index is 0
     */
    public Boolean getParaToBoolean(int index) {
        return toBoolean(getPara(index), null);
    }

    /**
     * Get para from url and conver to Boolean with default value if it is null.
     */
    public Boolean getParaToBoolean(int index, Boolean defaultValue) {
        return toBoolean(getPara(index), defaultValue);
    }

    private Date toDate(String value, Date defaultValue) {
        if (value == null || "".equals(value.trim()))
            return defaultValue;
        try {
            return new java.text.SimpleDateFormat(DateProvider.YYYY_MM_DD).parse(value);
        } catch (ParseException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Returns the value of a request parameter and convert to Date.
     *
     * @param name a String specifying the name of the parameter
     * @return a Date representing the single value of the parameter
     */
    public Date getParaToDate(String name) {
        return toDate(request.getParameter(name), null);
    }

    /**
     * Returns the value of a request parameter and convert to Date with a default value if it is null.
     *
     * @param name a String specifying the name of the parameter
     * @return a Date representing the single value of the parameter
     */
    public Date getParaToDate(String name, Date defaultValue) {
        return toDate(request.getParameter(name), defaultValue);
    }

    /**
     * Get all para from url and convert to Date
     */
    public Date getParaToDate() {
        return toDate(getPara(), null);
    }

    /**
     * Return HttpServletRequest. Do not use HttpServletRequest Object in constructor of Controller
     */
    public HttpServletRequest getRequest() {
        return request;
    }

    /**
     * Return HttpServletResponse. Do not use HttpServletResponse Object in constructor of Controller
     */
    public HttpServletResponse getResponse() {
        return response;
    }

    /**
     * Return HttpSession.
     */
    public HttpSession getSession() {
        return request.getSession();
    }

    /**
     * Return HttpSession.
     *
     * @param create a boolean specifying create HttpSession if it not exists
     */
    public HttpSession getSession(boolean create) {
        return request.getSession(create);
    }

    /**
     * Return a Object from session.
     *
     * @param key a String specifying the key of the Object stored in session
     */
    public <T> T getSessionAttr(String key) {
        HttpSession session = request.getSession(false);
        return session != null ? (T) session.getAttribute(key) : null;
    }

    /**
     * Store Object to session.
     *
     * @param key   a String specifying the key of the Object stored in session
     * @param value a Object specifying the value stored in session
     */
    public Controller setSessionAttr(String key, Object value) {
        request.getSession().setAttribute(key, value);
        return this;
    }

    /**
     * Remove Object in session.
     *
     * @param key a String specifying the key of the Object stored in session
     */
    public Controller removeSessionAttr(String key) {
        HttpSession session = request.getSession(false);
        if (session != null)
            session.removeAttribute(key);
        return this;
    }

    /**
     * Get cookie value by cookie name.
     */
    public String getCookie(String name, String defaultValue) {
        Cookie cookie = getCookieObject(name);
        return cookie != null ? cookie.getValue() : defaultValue;
    }

    /**
     * Get cookie value by cookie name.
     */
    public String getCookie(String name) {
        return getCookie(name, null);
    }

    /**
     * Get cookie value by cookie name and convert to Integer.
     */
    public Integer getCookieToInt(String name) {
        String result = getCookie(name);
        return result != null ? Integer.parseInt(result) : null;
    }

    /**
     * Get cookie value by cookie name and convert to Integer.
     */
    public Integer getCookieToInt(String name, Integer defaultValue) {
        String result = getCookie(name);
        return result != null ? Integer.parseInt(result) : defaultValue;
    }

    /**
     * Get cookie value by cookie name and convert to Long.
     */
    public Long getCookieToLong(String name) {
        String result = getCookie(name);
        return result != null ? Long.parseLong(result) : null;
    }

    /**
     * Get cookie value by cookie name and convert to Long.
     */
    public Long getCookieToLong(String name, Long defaultValue) {
        String result = getCookie(name);
        return result != null ? Long.parseLong(result) : defaultValue;
    }

    /**
     * Get cookie object by cookie name.
     */
    public Cookie getCookieObject(String name) {
        Cookie[] cookies = request.getCookies();
        if (cookies != null)
            for (Cookie cookie : cookies)
                if (cookie.getName().equals(name))
                    return cookie;
        return null;
    }

    /**
     * Get all cookie objects.
     */
    public Cookie[] getCookieObjects() {
        Cookie[] result = request.getCookies();
        return result != null ? result : new Cookie[0];
    }

    /**
     * Set Cookie to response.
     */
    public Controller setCookie(Cookie cookie) {
        response.addCookie(cookie);
        return this;
    }

    /**
     * Set Cookie to response.
     *
     * @param name            cookie name
     * @param value           cookie value
     * @param maxAgeInSeconds -1: clear cookie when close browser. 0: clear cookie immediately.  n>0 : max age in n seconds.
     * @param path            see Cookie.setPath(String)
     */
    public Controller setCookie(String name, String value, int maxAgeInSeconds, String path) {
        setCookie(name, value, maxAgeInSeconds, path, null);
        return this;
    }

    /**
     * Set Cookie to response.
     *
     * @param name            cookie name
     * @param value           cookie value
     * @param maxAgeInSeconds -1: clear cookie when close browser. 0: clear cookie immediately.  n>0 : max age in n seconds.
     * @param path            see Cookie.setPath(String)
     * @param domain          the domain name within which this cookie is visible; form is according to RFC 2109
     */
    public Controller setCookie(String name, String value, int maxAgeInSeconds, String path, String domain) {
        Cookie cookie = new Cookie(name, value);
        if (domain != null)
            cookie.setDomain(domain);
        cookie.setMaxAge(maxAgeInSeconds);
        cookie.setPath(path);
        response.addCookie(cookie);
        return this;
    }

    /**
     * Set Cookie with path = "/".
     */
    public Controller setCookie(String name, String value, int maxAgeInSeconds) {
        setCookie(name, value, maxAgeInSeconds, StringPool.SLASH, null);
        return this;
    }

    /**
     * Remove Cookie with path = "/".
     */
    public Controller removeCookie(String name) {
        setCookie(name, null, 0, StringPool.SLASH, null);
        return this;
    }

    /**
     * Remove Cookie.
     */
    public Controller removeCookie(String name, String path) {
        setCookie(name, null, 0, path, null);
        return this;
    }

    /**
     * Remove Cookie.
     */
    public Controller removeCookie(String name, String path, String domain) {
        setCookie(name, null, 0, path, domain);
        return this;
    }

    // --------

    /**
     * Get all para with separator char from url
     */
    public String getPara() {
        if ("".equals(urlPara))    // urlPara maybe is "" see ActionMapping.getAction(String)
            urlPara = null;
        return urlPara;
    }

    /**
     * Get para from url. The index of first url para is 0.
     */
    public String getPara(int index) {
        if (index < 0)
            return getPara();

        if (urlParaArray == null) {
            if (urlPara == null || "".equals(urlPara))    // urlPara maybe is "" see ActionMapping.getAction(String)
                urlParaArray = NULL_URL_PARA_ARRAY;
            else
                urlParaArray = urlPara.split(URL_PARA_SEPARATOR);

            for (int i = 0; i < urlParaArray.length; i++)
                if ("".equals(urlParaArray[i]))
                    urlParaArray[i] = null;
        }
        return urlParaArray.length > index ? urlParaArray[index] : null;
    }

    /**
     * Get para from url with default value if it is null or "".
     */
    public String getPara(int index, String defaultValue) {
        String result = getPara(index);
        return result != null && !"".equals(result) ? result : defaultValue;
    }

    /**
     * Get para from url and conver to Integer. The first index is 0
     */
    public Integer getParaToInt(int index) {
        return toInt(getPara(index), null);
    }

    /**
     * Get para from url and conver to Integer with default value if it is null.
     */
    public Integer getParaToInt(int index, Integer defaultValue) {
        return toInt(getPara(index), defaultValue);
    }

    /**
     * Get para from url and conver to Long.
     */
    public Long getParaToLong(int index) {
        return toLong(getPara(index), null);
    }

    /**
     * Get para from url and conver to Long with default value if it is null.
     */
    public Long getParaToLong(int index, Long defaultValue) {
        return toLong(getPara(index), defaultValue);
    }

    /**
     * Get all para from url and convert to Integer
     */
    public Integer getParaToInt() {
        return toInt(getPara(), null);
    }

    /**
     * Get all para from url and convert to Long
     */
    public Long getParaToLong() {
        return toLong(getPara(), null);
    }

    /**
     * Get model from http request.
     */
    public <T> T getModel(Class<T> modelClass) {
        return (T) ModelInjector.inject(modelClass, request, false);
    }

    /**
     * Get model from http request.
     */
    public <T> T getModel(Class<T> modelClass, String modelName) {
        return (T) ModelInjector.inject(modelClass, modelName, request, false);
    }

    // TODO public <T> List<T> getModels(Class<T> modelClass, String modelName) {}

    // --------
    private MultipartRequest multipartRequest;

    /**
     * Get upload file from multipart request.
     */
    public List<UploadFile> getFiles(String saveDirectory, Integer maxPostSize, String encoding) {
        if (multipartRequest == null) {
            multipartRequest = new MultipartRequest(request, saveDirectory, maxPostSize, encoding);
            request = multipartRequest;
        }
        return multipartRequest.getFiles();
    }

    public UploadFile getFile(String parameterName, String saveDirectory, Integer maxPostSize, String encoding) {
        getFiles(saveDirectory, maxPostSize, encoding);
        return getFile(parameterName);
    }

    public List<UploadFile> getFiles(String saveDirectory, int maxPostSize) {
        if (multipartRequest == null) {
            multipartRequest = new MultipartRequest(request, saveDirectory, maxPostSize);
            request = multipartRequest;
        }
        return multipartRequest.getFiles();
    }

    public UploadFile getFile(String parameterName, String saveDirectory, int maxPostSize) {
        getFiles(saveDirectory, maxPostSize);
        return getFile(parameterName);
    }

    public List<UploadFile> getFiles(String saveDirectory) {
        if (multipartRequest == null) {
            multipartRequest = new MultipartRequest(request, saveDirectory);
            request = multipartRequest;
        }
        return multipartRequest.getFiles();
    }

    public UploadFile getFile(String parameterName, String saveDirectory) {
        getFiles(saveDirectory);
        return getFile(parameterName);
    }

    public List<UploadFile> getFiles() {
        if (multipartRequest == null) {
            multipartRequest = new MultipartRequest(request);
            request = multipartRequest;
        }
        return multipartRequest.getFiles();
    }

    public UploadFile getFile() {
        List<UploadFile> uploadFiles = getFiles();
        return uploadFiles.size() > 0 ? uploadFiles.get(0) : null;
    }

    public UploadFile getFile(String parameterName) {
        List<UploadFile> uploadFiles = getFiles();
        for (UploadFile uploadFile : uploadFiles) {
            if (uploadFile.getParameterName().equals(parameterName)) {
                return uploadFile;
            }
        }
        return null;
    }

    // i18n features --------

    /**
     * Write Local to cookie
     */
    public Controller setLocaleToCookie(Locale locale) {
        setCookie(I18N_LOCALE, locale.toString(), I18N.getI18nMaxAgeOfCookie());
        return this;
    }

    public Controller setLocaleToCookie(Locale locale, int maxAge) {
        setCookie(I18N_LOCALE, locale.toString(), maxAge);
        return this;
    }

    public String getText(String key) {
        return I18N.getText(key, getLocaleFromCookie());
    }

    public String getText(String key, String defaultValue) {
        return I18N.getText(key, defaultValue, getLocaleFromCookie());
    }

    private Locale getLocaleFromCookie() {
        Cookie cookie = getCookieObject(I18N_LOCALE);
        if (cookie != null) {
            return I18N.localeFromString(cookie.getValue());
        } else {
            Locale defaultLocale = I18N.getDefaultLocale();
            setLocaleToCookie(defaultLocale);
            return I18N.localeFromString(defaultLocale.toString());
        }
    }

    /**
     * Keep all parameter's value except model value
     */
    public Controller keepPara() {
        Map<String, String[]> map = request.getParameterMap();
        for (Entry<String, String[]> e : map.entrySet()) {
            String[] values = e.getValue();
            if (values.length == 1)
                request.setAttribute(e.getKey(), values[0]);
            else
                request.setAttribute(e.getKey(), values);
        }
        return this;
    }

    /**
     * Keep parameter's value names pointed, model value can not be kept
     */
    public Controller keepPara(String... names) {
        for (String name : names) {
            String[] values = request.getParameterValues(name);
            if (values != null) {
                if (values.length == 1)
                    request.setAttribute(name, values[0]);
                else
                    request.setAttribute(name, values);
            }
        }
        return this;
    }

    /**
     * Convert para to special type and keep it
     */
    public Controller keepPara(Class type, String name) {
        String[] values = request.getParameterValues(name);
        if (values != null) {
            if (values.length == 1)
                try {
                    request.setAttribute(name, TypeConverter.convert(type, values[0]));
                } catch (ParseException ignored) {
                }
            else
                request.setAttribute(name, values);
        }
        return this;
    }

    public Controller keepPara(Class type, String... names) {
        if (type == String.class)
            return keepPara(names);

        if (names != null)
            for (String name : names)
                keepPara(type, name);
        return this;
    }

    public Controller keepModel(Class modelClass, String modelName) {
        Object model = ModelInjector.inject(modelClass, modelName, request, true);
        request.setAttribute(modelName, model);
        return this;
    }

    public Controller keepModel(Class modelClass) {
        String modelName = StringKit.firstCharToLowerCase(modelClass.getSimpleName());
        keepModel(modelClass, modelName);
        return this;
    }

    /**
     * Create a token.
     *
     * @param tokenName        the token name used in view
     * @param secondsOfTimeOut the seconds of time out, secondsOfTimeOut >= Const.MIN_SECONDS_OF_TOKEN_TIME_OUT
     */
    public void createToken(String tokenName, int secondsOfTimeOut) {
        com.jfinal.token.TokenManager.createToken(this, tokenName, secondsOfTimeOut);
    }

    /**
     * Create a token with default token name and with default seconds of time out.
     */
    public void createToken() {
        createToken(Const.DEFAULT_TOKEN_NAME, Const.DEFAULT_SECONDS_OF_TOKEN_TIME_OUT);
    }

    /**
     * Create a token with default seconds of time out.
     *
     * @param tokenName the token name used in view
     */
    public void createToken(String tokenName) {
        createToken(tokenName, Const.DEFAULT_SECONDS_OF_TOKEN_TIME_OUT);
    }

    /**
     * Check token to prevent resubmit.
     *
     * @param tokenName the token name used in view's form
     * @return true if token is correct
     */
    public boolean validateToken(String tokenName) {
        return com.jfinal.token.TokenManager.validateToken(this, tokenName);
    }

    /**
     * Check token to prevent resubmit  with default token key ---> "JFINAL_TOKEN_KEY"
     *
     * @return true if token is correct
     */
    public boolean validateToken() {
        return validateToken(Const.DEFAULT_TOKEN_NAME);
    }

    /**
     * Return true if the para value is blank otherwise return false
     */
    public boolean isParaBlank(String paraName) {
        String value = request.getParameter(paraName);
        return value == null || value.trim().length() == 0;
    }

    /**
     * Return true if the urlPara value is blank otherwise return false
     */
    public boolean isParaBlank(int index) {
        String value = getPara(index);
        return value == null || value.trim().length() == 0;
    }

    /**
     * Return true if the para exists otherwise return false
     */
    public boolean isParaExists(String paraName) {
        return request.getParameterMap().containsKey(paraName);
    }

    /**
     * Return true if the urlPara exists otherwise return false
     */
    public boolean isParaExists(int index) {
        return getPara(index) != null;
    }

    // ----------------
    // render below ---
    private static final RenderFactory renderFactory = RenderFactory.me();

    /**
     * Hold Render object when invoke renderXxx(...)
     */
    private Render render;

    public Render getRender() {
        return render;
    }

    /**
     * Render with any Render which extends Render
     */
    public void render(Render render) {
        this.render = render;
    }

    /**
     * Render with view use default type Render configured in JFinalConfig
     */
    public void render(String view) {
        render = renderFactory.getRender(view);
    }

    /**
     * Render with jsp view
     */
    public void renderJsp(String view) {
        render = renderFactory.getJspRender(view);
    }

    /**
     * Render with freemarker view
     */
    public void renderFreeMarker(String view) {
        render = renderFactory.getFreeMarkerRender(view);
    }

    /**
     * Render with velocity view
     */
    public void renderVelocity(String view) {
        render = renderFactory.getVelocityRender(view);
    }

    /**
     * Render with json
     * <p/>
     * Example:<br>
     * renderJson("message", "Save successful");<br>
     * renderJson("users", users);<br>
     */
    public void renderJson(String key, Object value) {
        render = renderFactory.getJsonRender(key, value);
    }

    /**
     * Render with json
     */
    public void renderJson() {
        render = renderFactory.getJsonRender();
    }

    /**
     * Render with attributes set by setAttr(...) before.
     * <p/>
     * Example: renderJson(new String[]{"blogList", "user"});
     */
    public void renderJson(String[] attrs) {
        render = renderFactory.getJsonRender(attrs);
    }

    /**
     * Render with json text.
     * <p/>
     * Example: renderJson("{\"message\":\"Please input password!\"}");
     */
    public void renderJson(String jsonText) {
        render = renderFactory.getJsonRender(jsonText);
    }

    /**
     * Render json with object.
     * <p/>
     * Example: renderJson(new User().set("name", "JFinal").set("age", 18));
     */
    public void renderJson(Object object) {
        render = renderFactory.getJsonRender(object);
    }

    /**
     * Render with text. The contentType is: "text/plain".
     */
    public void renderText(String text) {
        render = renderFactory.getTextRender(text);
    }

    /**
     * Render with text and content type.
     * <p/>
     * Example: renderText("<user id='5888'>James</user>", "application/xml");
     */
    public void renderText(String text, String contentType) {
        render = renderFactory.getTextRender(text, contentType);
    }

    /**
     * Forward to an action
     */
    public void forwardAction(String actionUrl) {
        render = new ActionRender(actionUrl);
    }

    /**
     * Render with file
     */
    public void renderFile(String fileName) {
        render = renderFactory.getFileRender(fileName);
    }

    /**
     * Render with file
     */
    public void renderFile(File file) {
        render = renderFactory.getFileRender(file);
    }

    /**
     * Redirect to url
     */
    public void redirect(String url) {
        render = renderFactory.getRedirectRender(url);
    }

    /**
     * Redirect to url
     */
    public void redirect(String url, boolean withQueryString) {
        render = renderFactory.getRedirectRender(url, withQueryString);
    }

    /**
     * Render with view and status use default type Render configured in JFinalConfig
     */
    public void render(String view, int status) {
        render = renderFactory.getRender(view);
        response.setStatus(status);
    }

    /**
     * Render with url and 301 status
     */
    public void redirect301(String url) {
        render = renderFactory.getRedirect301Render(url);
    }

    /**
     * Render with url and 301 status
     */
    public void redirect301(String url, boolean withQueryString) {
        render = renderFactory.getRedirect301Render(url, withQueryString);
    }

    /**
     * Render with view and errorCode status
     */
    public void renderError(int errorCode, String view) {
        throw new ActionException(errorCode, renderFactory.getErrorRender(errorCode, view));
    }

    /**
     * Render with render and errorCode status
     */
    public void renderError(int errorCode, Render render) {
        throw new ActionException(errorCode, render);
    }

    /**
     * Render with view and errorCode status configured in JFinalConfig
     */
    public void renderError(int errorCode) {
        throw new ActionException(errorCode, renderFactory.getErrorRender(errorCode));
    }

    /**
     * Render nothing, no response to browser
     */
    public void renderNull() {
        render = renderFactory.getNullRender();
    }

    /**
     * Render with javascript text. The contentType is: "text/javascript".
     */
    public void renderJavascript(String javascriptText) {
        render = renderFactory.getJavascriptRender(javascriptText);
    }

    /**
     * Render with html text. The contentType is: "text/html".
     */
    public void renderHtml(String htmlText) {
        render = renderFactory.getHtmlRender(htmlText);
    }
}












